As society gradually evolves, the light industry requires various functions, such as individual and group control. Furthermore, as an environmental problem becomes serious, there is an increasing need for a light capable of reducing energy.
Accordingly, after a light-emitting diode (hereinafter referred to as an “LED”) which is eco-friendly and has high energy efficiency was developed, there is a tendency that LED-related technologies become high efficiency very rapidly due to technology competitiveness, are spread into common light and high efficiency light markets due to the development of a white LED, continue to replace existing lights.
An LED driving circuit may implement various circuits depending on a design object. In this case, the LED driving circuit has a strong influence on efficiency of a driving circuit and the lifespan of an LED depending on uses, the driving characteristic of an LED, and the configuration of an LED array.
Meanwhile, in order to drive such an LED light, a power supply apparatus is commonly connected.
The power supply apparatus functions to receive external power and to convert the external power into power for driving the LED light. For example, a constant current type power supply apparatus converts an AC applied thereto into a direct current (DC) and supplies the DC to an LED light, that is, a light source.
As the range of use of an LED light is widened, a power supply apparatus for driving the LED light is designed in various ways from several tens of watts (W) to several hundreds of watts (W). To secure insulation with the outside becomes more important because a danger of an electric shock is increased as the capacity is increased.
Furthermore, as people's interest in lights recently gradually increases along with the improvement of quality of life, a current light device requires more than it turns on a light using a switch. That is, a current light device is developing into a more advanced form, such as producing various atmospheres depending on indoor uses or automatically adjusting luminous intensity properly depending on surrounding luminous intensity. A light device that evolves as described above is internationally used based on digital addressable lighting interface (DALI) communication.